LHIP: Left-Head-Corner Island Parser Compiler

LHIP is a left-head-corner island parser compiler. The system compiles
grammar rules to Prolog code in much the same way as the Prolog DCG
system does. The rules themselves are an extended version of the DCG
rules, allowing optional constituents, negation, disjunction, the
specification of adjacency, and the ability to mark multiple heads in
a rule body.